Ultimate Tic-Tac-Toe

Nine small boards inside one big one. The square you play in decides which board your opponent has to play in next.

What makes it different

Win a small board and you claim its square. Win three of those in a row and you win the game. Every move is two decisions — where to go, and where you are willing to send your opponent.

There are no accounts to create, no sign-in wall and no ads interrupting a match. Classic 3×3 is included, and on Master it is genuinely unbeatable: that game is solved, so the best anyone can do is draw. Ultimate on Master is a deep search rather than perfect play, and it can be beaten.